<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>姓名案例-插值</title>
    <script src="../js/vue.js"></script>
</head>
<body>
    <div id="root">
        姓：<input type="text" v-model="firstname"><br/>
        名：<input type="text" v-model="lastname"><br/>
        全名：<span>{{firstname.slice(0,3)}}-{{lastname}}</span>
        <!--slice（0，3）截取前三位-->
    </div>
</body>

<script>
    new Vue({
        el:'#root',
        data:{
          firstname:'张',
          lastname:'三'
        }
    })
</script>

</html>